Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare it is a non-read-only, idempotent, non-destructive edit, so the safety profile is covered. The description adds only that it returns the edit result and defers to server instructions, without saying what the edit result contains or any constraints (e.g., clip must have audio). Adequate but thin for a mutation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, front-loaded with the core action and range. The trailing pointer to 'server instructions' is slightly deflective but does not bloat the text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be explained, and annotations cover mutation safety. However, nothing explains the preview parameter's effect or whether panning applies only to clips with audio, leaving gaps for a 4-parameter edit tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 75% and the pan range is already documented in the schema; the description merely restates -1..1. The preview parameter and timeline_id handle semantics are not touched on in the description, so it adds little beyond structured fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete verb and resource ('Place a clip's sound left (-1) to right (1)'), which unambiguously identifies stereo panning and separates it from gain/fade siblings. It does not explicitly contrast with audio.set_gain or audio.set_master, but the word 'pan' plus the -1..1 range does the differentiation implicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use it (to position a clip's audio in the stereo field) but gives no explicit conditions, prerequisites, or alternatives such as audio.set_gain or audio.set_master. An agent must infer usage from the verb alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.